Generating Consensus Syndrome Case Definitions

September 24-25, 2007Pittsburgh, PA

Hosted by Wendy Chapman and John Dowling Funded by ISDS

ObjectiveGenerate explicit consensus

syndrome definitions based on current syndromic surveillance

practice

RespiratoryGastrointestinal

Fever/Constitutional/ILI

Overview

• Purpose of meeting

• Baseline consensus syndromes

• Coming to Consensus

• Consensus Definitions

• Future goals

Clinical Condition experienced by a patient

Complaint Classifier

Syndrome CategoryClinical Condition Concept

(Preprocess)Classify

Cough (C00529)Headache (C00421)

RespiratoryNeurological

Admission complaint

“cough/headache”

Purpose of Meeting

Purpose of Meeting

Aim 1

• Catalogue and characterize existing chief complaint classifiers and the syndromic categories they map to

Aim 2

• Develop consensus syndrome categories and definitions, using the catalogue of existing definitions as a starting point

Possible Uses for Standardized Consensus Syndromic Definitions

Research

• Compare chief complaint classifiers against each other using standard definitions

• Generate a list of clinical conditions important for surveillance– Target for NLP systems to extract from reports

• Generate a standardized list of conditions that can be validated for predictive power

• Develop a set of chief complaints with standardized annotations for research and development

Public Health

• Provide a catalogue of what real systems across the country are surveilling

• Provide a benchmark for comparing different syndrome definitions against each other

– Examination

– Research/validation studies

Consensus Syndrome Definitions

Generating Consensus Syndromes

• Compiled syndrome definitions from ten surveillance systems

– Clinical conditions mapped to syndromes

• Counted how many times each condition occurred with each syndrome

• Removed conditions that did not meet inclusion criteria

• Discussed

– which syndromes to include in reference

– which clinical conditions comprise each syndrome

Before the meeting

Characterize Currently Used Syndromic Definitions

1. Collated condition-syndrome maps for 10 syndromic surveillance systems– RODS– BioPortal (Arizona)– Seattle, King County– Biosense– NCDetect– Aegis (Harvard)– Essence– New York State– Boston Public Health Dept– New York City

2. Created a union of all syndromes(Respiratory, GI, Fever/Constitutional/ILI, Neurological)

• Merged identical syndromes together

System 1: Respiratory

System 2: Respiratory, Upper Resp, Lower Resp

System 3: Respiratory

Resp U Resp L Resp

18 unique syndromes

• Conditions can be signs, symptoms, findings, or diagnoses

• Conditions should comprise a single problem

– Cough—not cough/SOB

• Conditions should be those that a patient may present with at an acute care visit

• Conditions should be reasonably described in admit complaints

• Conditions should be directly related to the organ system

Inclusion Criteria for Clinical Conditions

3. Filtered and sorted clinical conditions indicating each syndrome

• From an initial list of 91 conditionsCCC-EDS (Thompson)• If anyone used condition

• Keep the condition in current list

• For additional conditions• If condition did not exist in current list

• Add new condition OR• Leave condition out

Added: BronchitisInfluenzaChillsPleural effusion

Why: Signs, symptoms not in CCC-EDSGeneral diagnoses

3. Filtered and sorted clinical conditions indicating each syndrome

• Created an initial list of 91 conditionsCCC-EDS (Thompson)• If anyone used condition

• Keep the condition in current list

• For additional conditions• If condition did not exist in current list

• Add new condition OR• Leave condition out

Not Added: Crohn’s Disease

DiverticulitisPulmonaryInfection

Why: Specific diagnosesBroad bins

Title Resp U Resp L Resp

APNEA 2

ASTHMA ATTACK 2 1

BREATHING DIFFICULTY (DYSPNEA) 2 1

BRUISE

CARDIORESPIRATORY ARREST 2 1

CHEST PAIN 1

COUGH 3 1

COUGHING UP BLOOD (HEMOPTYSIS) 3 1

CROUP 3 1

59 of 91 CCC-EDS conditions were used

78 new conditions added

31 conditions considered synonyms (not added)

36 additional conditions not added

136 total conditions

4. Counted frequency of each condition for each syndrome in combined list

Maximum Frequency

10 – Respiratorycough, breathing difficulty, coughing up

blood

Number of Singletons

128

Coming to Consensus on Reference Syndrome Definitions

Pittsburgh MeetingSeptember 24-25, 2007

• 18 participants

– 13 attended

• Set guidelines for syndrome definition generation

– purpose for syndrome definitions

• Viewed baseline syndromes

• Argued about

– Which syndromes to include

– Which conditions to include

Participants

• Craig Hales• Carol Sniegoski• Karen Olson• Jeremy Espino• Cathy Larson• Mikaela Keller• Lori Hutwagner• David Thompson• Dennis Cochrane

• Marc Paladini• Julia Gunn• Atar Baer• Bill Lober• Matt Schoeler• John Dowling• Rebecca Noe• Peter Elkin• Wendy Chapman

Will we accomplish

anything or just argue?

Will one person be

headstrong and not agree with the rest?

Who are we to generate reference

definitions?

Will they like Pittsburgh?

Am I overlooking anybody?

Syndrome Definition purposeTo assist public health in monitoring, characterizing, detecting, and responding to changes in population health based on patients’ initial clinical presentation of acute outbreaks and exposures

What Syndromes Do People Use?Ten surveillance systems

Resp Upper Lower Asthma Cold10 1 1 2 1

Respiratory

GI Abd Pain Bloody Diarrhea Diarrhea Vomiting9 1 1 2 2

Gastrointestinal

Const Febrile ILI FeverFlu Sepsis4 4 2 1 1

Constitutional

Neurological Meningoencephalitis Shock_coma8 3 1

Neurological

Reference Syndrome Definitions

• Focused on three syndromes– Respiratory– GI– Constitutional/ILI

• Solution to many arguments– Create a sensitive and a specific syndrome

• Respiratory (sensitive, specific)• GI (sensitive, specific)

– Create two syndromes (similar to sens and spec)• Constitutional• ILI

6 consensus reference syndrome definitions

Respiratory Syndrome

48 conditions

2616

Sensitive Specific

BREATHING DIFFICULTY 1 1

COUGH 1 1

HEMOPTYSIS 1 1

ASTHMA ATTACK 1 1

CROUP 1 1

PNEUMONIA 1 1

WHEEZING 1 1

RUNNY OR STUFFY NOSE 1 0

PLEURITIC PAIN 1 0

SORE THROAT 1 0

URI 1 0

…

Clinical Condition Sens Spec

25 conditions

6 3

Sensitive Specific

Clinical Condition Sens Spec

ABDOMINAL PAIN 1 0

DIARRHEA 1 1

VOMITING 1 1

NAUSEA 1 0

GASTROENTERITIS 1 1

DEHYDRATION 1 0

GI Syndrome

32 conditions

12

Constitutional Syndrome

IRRITABLE BABY

FEVER

WEAKNESS

ANOREXIA

VIRAL SYNDROME

FAINTNESS

MALAISE

BODY ACHES

GENERAL ILLNESS

CHILLS

LYMPHADENOPATHY

SWEATING

17 conditions

12

Influenza-like Illness Syndrome

COUGH

SORE THROAT

FEVER

WEAKNESS

VIRAL SYNDROME

BODY ACHES

BRONCHIOLITIS

PNEUMONIA

UPPER RESPIRATORY INFECTION

MALAISE

CHILLS

INFLUENZA

Reasons for Excluding a Condition• Not specific to the organ system

– Fever in Respiratory

• Not systemic

– Headache in Constitutional

• Not specific enough to a disease of interest

– Abdominal Pain in Specific Gastrointestinal

• Not the primary presentation of a significant illness

– Earache in Specific Respiratory

• A related concept or synonym to another concept

– LLQ Abdominal pain

Future Goals

Future

• Post syndrome definitions on ISDS Wiki

Add

– Related concepts/synonyms

– Localized textual variants

– Linguistic variants

• Write paper on the meeting and on the definitions

• Begin collaborative research studies

– Anyone want to collaborate?

• Generate repository of chief complaints

– Generate annotations into syndrome definitions

Thank you ISDS